Search results for: soil-nutrient-bioavailability

Soil Nutrient Bioavailability

Author : Stanley A. Barber
File Size : 65.21 MB
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This richly illustrated edition of an established classic deals with the chemistry and biology of soil nutrient availability. Provides information regarding the elements present in soils and the extent to which these elements can be used by plants in order to grow. Nutrient uptake by plant roots, rhizosphere microorganisms and application of the mechanistic uptake model as well as such elements as phosphorus, potassium and water are among the topics discussed.

Thermodynamics of Soil Nutrient Bioavailability

Author : Kodoth Prabhakaran Nair
File Size : 36.47 MB
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This book focusses on the thermodynamics of soil nutrient bioavailability, and in particular the most important plant nutrients such as, phosphorus and potassium, among major nutrients, and zinc among micronutrients. It proposes a paradigm shift in the approach to global soil testing procedures. Historically, soil testing has been used to quantify availability of essential plant nutrients to field-grown crops. However, contemporary soil tests are based on philosophies and procedures developed several decades ago, without significant changes in their general approach. For a soil test to be accurate, one needs to clearly understand the physico-chemico-physiological processes at the soil-root interface and, an understanding of soils and plant root systems as polycationic systems is essential. It is this knowledge that leads to sound prescriptive soil nutrient management inasmuch as soil nutrient bioavailability vis-à-vis fertilizer application is concerned, because, of all the factors which govern sustainability in crop production, the nutrient factor is the most important, yet, it is also least resilient to management. This book provides a clear scientific basis of the thermodynamics of soil nutrient bio availability, which routine soil testing does not provide

Nutrient Acquisition by Plants

Author : Hormoz BassiriRad
File Size : 42.11 MB
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This is an integrated review of the mechanisms controlling plant nutrient uptake and how plants respond to changes in the environment. Among key topics covered are: soil nutrient bioavailability; root responses to variations in nutrient supply; nitrogen fixation; root architecture; life span; mycorrhizae; responses to climate change. The book helps us understand the mechanisms that govern present-day plant communities and to predict the response of plants to a changing climate.

Nutrient Acquisition by Plants

Author : Hormoz BassiriRad
File Size : 57.48 MB
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Soil, decomposition, mineralization, litter, humus, nitrogen, roots.

Sources of Bioavailable Particulate Nutrients

Author : Joanne Burton
File Size : 23.13 MB
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In this pilot project a limited number of surface and subsurface soil samples were collected from the Johnstone and Burdekin-Bowen Catchments. Samples covered a range of major soil types and land uses. Fine sediments and their parent soils were analysed to characterise the various pools and processes of the carbon, nitrogen and phosphorus cycles. Methods followed those used to assess nutrient bioavailability to agricultural crops, thereby allowing particulate nutrient bioavailability in sediments and their parent soils to be inferred under simulated freshwater and marine conditions.

Encyclopedia of Soil Science

Author : Rattan Lal
File Size : 79.77 MB
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"Upholding the high standard of quality set by the previous edition, this two-volume second edition offers a vast array of recent peer-reviewed articles. It showcases research and practices with added sections on ISTIC-World Soil Information, root growth and agricultural management, nitrate leaching management, podzols, paramos soils, water repellant soils, rare earth elements, and more. With hundreds of entries covering tillage, irrigation, erosion control, ground water, and soil degradation, the book offers quick access to all branches of soil science, from mineralology and physics, to soil management, restoration, and global warming."--Publisher's website.

Nonacid Cation Bioavailability in Sand Rootzones

Author : Micah Sharpe Woods
File Size : 84.78 MB
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Soil nutrient analyses are used as indices of nutrient availability to plant roots. The 1 M NH4OAc, Mehlich 3, Morgan, 1:5 H2O, and 0.01 M SrCl2 extracting solutions were evaluated for measurement of extractable nonacid cations in a calcareous sand rootzone. The 1:5 H2O and 0.01 M SrCl2 tests adjusted to sample pH during the extraction process, but the 1 M NH4OAc, Mehlich 3, and Morgan tests did not adjust to sample pH. When comparing the extraction methods for their ability to detect K-induced changes in extractable Ca or Mg from a calcareous sand, the methods that adjusted to sample pH were sensitive to the changes, but the non-adjusting methods were not. The 0.01 M SrCl 2 method also predicted cation exchange capacity (CEC). In a selection of 37 sands and 17 soils, CEC was estimated by summation of the nonacid cations extracted by soil nutrient analyses. These CEC estimates were compared to CEC measured by compulsive exchange of Mg2+ for Ba2+ . In sand samples, the 0.01 M SrCl2 estimates of CEC were very similar to measured CEC, but the 1 M NH 4OAc, Mehlich 3, and Morgan estimates of CEC were larger than the measured CEC. The nonacid cations extracted by 0.01 M SrCl2 can be used to estimate CEC in calcareous and non-calcareous sands and soils. All extracting solutions were able to detect increased K availability to creeping bentgrass [Agrostis stolonifera var. palustris (Huds.) Farw] in field and greenhouse experiments. Cation exchange membranes detected increased K supply rates in field plots to which K fertilizer had been applied. However, leaf K content varied between sampling dates, so although leaf K was related to soil K at individual dates, it was difficult to predict creeping bentgrass K content from soil nutrient analyses of sand rootzones. By expressing leaf K as the concentration of K in tissue water (K w), variability associated with changes in leaf water content between sampling dates was reduced. Performance of L-93 creeping bentgrass in a calcareous sand classified as low in K was not affected by K fertilizer application or by changes in soil K, Ca, and Mg. These results suggest that current interpretations of nonacid cation soil test sufficiency levels should be reevaluated for sand rootzones. Under greenhouse conditions, A-1 creeping bentgrass grown in sands with pH ranging from 5.0 to 8.5 had leaf Ca, Mg, and K content within sufficiency levels, even in sands classified as low in Mehlich 3 extractable Ca, Mg, and K. Testing methods that adjust to sample pH were suitable for assessing nonacid cation availability in calcareous and non-calcareous sands. Future research should more clearly identify the relationship between extractable nonacid cations and turfgrass growth.

Diagnosis Correction of Soil Nutrient Limitations in Intensively Managed Southern Pine Forests

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Forest productivity is one manner to sequester carbon and it is a renewable energy source. Likewise, efficient use of fertilization can be a significant energy savings. To date, site-specific use of fertilization for the purpose of maximizing forest productivity has not been well developed. Site evaluation of nutrient deficiencies is primarily based on empirical approaches to soil testing and plot fertilizer tests with little consideration for soil water regimes and contributing site factors. This project uses mass flow diffusion theory in a modeling context, combined with process level knowledge of soil chemistry, to evaluate nutrient bioavailability to fast-growing juvenile forest stands growing on coastal plain Spodosols of the southeastern U.S. The model is not soil or site specific and should be useful for a wide range of soil management/nutrient management conditions. In order to use the model, field data of fast-growing southern pine needed to be measured and used in the validation of the model. The field aspect of the study was mainly to provide data that could be used to verify the model. However, we learned much about the growth and development of fast growing loblolly. Carbon allocation patterns, root shoot relationships and leaf area root relationships proved to be new, important information. The Project Objectives were to: (1) Develop a mechanistic nutrient management model based on the COMP8 uptake model. (2) Collect field data that could be used to verify and test the model. (3) Model testing.

Chemical Bioavailability in Terrestrial Environments

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This book begins with an overview of current thinking on bioavailability, its definition, cutting-edge research in speciation and advancement in tools for assessing chemical bioavailability in the terrestrial environment. The second section of the book focuses on the role of chemical speciation in bioavailability. Section three addresses bioavailability and ecotoxicity of contaminants and leads into the next section on bioavailability of nutrients and agrichemicals. Subsequent sections provide an overview of tools currently being used and new cutting-edge techniques to assess contaminant bioavailability. The last section of the book builds on previous sections in relating bioavailability to risk assessment and how this could be used for managing risks associated with contaminated land. Provides the latest information on developing concepts and definitions of bioavailability Includes a discussion of bioavailability and ecotoxicity of contaminants and bioavailability of nutrients and agrichemicals for applications in agriculture Analyzes tools for assessing bioavailability and the role of bioavailability in risk assessment and remediation

Amazonian Dark Earths

Author : Johannes Lehmann
File Size : 85.57 MB
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Dark Earths are a testament to vanished civilizations of the Amazon Basin, but may also answer how large societies could sustain intensive agriculture in an environment of infertile soils. This book examines their origin, properties, and management. Questions remain: were they intentionally produced or a by-product of habitation. Additional new and multidisciplinary perspectives by leading experts may pave the way for the next revolution in soil management in the humid tropics.